HCS+T7F™

Tips and Frequently Asked Questions

Please review these notes before contacting McTrans for technical support, as it is likely your question will be answered by the FAQs and tips below. If your question is not answered, feel free to contact us for assistance! Ph: (352) 392-0378 Email: mctrans@ce.ufl.edu.

For quicker service, please have your HCS+T7F registration number available if you call. It can be found by choosing Help then “About HCS+T7F” on the Main Menu. Your registration number is just below the header information.

HCS+T7F is distributed as an office license that includes technical support (automatic updates, downloadable updates, toll-free telephone assistance, data file review, etc.) for the first year. Thereafter, an annual support subscription must be maintain to continue these services, but no more upgrade fees are required.

Does the upgrade from HCS+ to HCS+T7F add new modules, upgrade only changed ones, or is it a completely new set?

This release comprises a complete installation of HCS+ (release 5.3) implementing all approved changes to the procedures defined in the 2000 Highway Capacity Manual (HCM 2000) to date, adding HCS+Interchanges to automate the methodology in the recently approved HCM Chapter 26 for Interchange Ramps Terminals and integrating TRANSYT-7F (release 11.2) with the ability to import HCS-Signals and HCS-Interchanges data files for optimization and one-touch CORSIM animation.

Do I need to uninstall the previous version(s) of HCS?

HCS+T7F is a separate installation and does not automatically uninstall HCS+ (or any previous version). Although uninstalling the previous version(s) is recommended to avoid conflicts and confusion for most users, allowing multiple versions to co-exist on one computer can be managed if there is a need. Some issues to be aware of include: double-clicking on a data file within Windows Explorer will typically load it in the latest version; right clicking on a data file within Windows Explorer to use ‘Open With’ can show multiple versions without information to tell them apart; and information like agency data, default file paths, some default data, recent file list, window position, etc. is stored in the Windows registry, and changing this for one version will likely affect the others.

What are the minimum computer requirements for this version?

HCS+T7F is a typical Windows installation and the system must meet the following minimum requirements including Windows 2000 or newer, 128MB RAM, VGA+ Monitor and 300 MB Hard Disk space available. This will be a completely new installation, separate from any existing version. The installation program will present a license agreement, which must be agreed to for the installation to proceed.

Are there any issues with running HCS+T7F in Windows Vista?

No issues have been discovered in testing or reported by users, except for the requirement to download a free file from Microsoft to enable the on-board Help system as noted in the Known Issues below.

Do I have to have TSIS-CORSIM installed for the one-touch animation feature to work?

Yes, TSIS-CORSIM is not a part of the HCS+T7F package and must be installed separately for this feature to work. HCS+ and T7F both generate CORISM input files for automatically running CORSIM to produce the output files necessary for creating the TRAFVU animation.

Where is the new Interchanges module applicable?

This analysis covers the unique relationship between two signalized intersections controlling the ramps from an intersecting freeway. It will analyze diamond, six partial cloverleaf and single-point urban interchange designs, accounting for internal queuing, additional lost times, etc. to generate levels of service for each origin-destination movement.

Does the median type make a difference in a Two-Way Stop-Controlled analysis?

The computation of two-stage gap acceptance differs for the minor-street thru movements depending on the type of median. A “Raised Curb” median assumes the minor-street thru can utilize this storage to perform the movement in two steps. A “TWLTL” median will assume the minor-street thru movement will be accomplished in one stage.

Why won’t my formatted report print on one page?

Since these reports use the Internet Explorer for display and printing, adjustments may need to be made there for these reports to print on one page. To suppress the automatic header and/or footer, simply blank the appropriate field(s) in the “File > Page Setup” screen. Setting margins to 0.25″ on this screen is also advisable. You may also have to reduce the text size in View > Text Size.

Why does the last field with data sometimes not get used in the calculations or saved in the file?

Users must be sure to hit Tab, Enter or click into another field before viewing or printing results to ensure the last entry has been recognized. When a data file is saved, the last entry is automatically stored.

What is the advantage in running a Multiple-Period analysis in Signals?

The main reason to using a multiple-period analysis is to model the unmet demand that may exist from one 15-minute period to the next in oversaturated conditions. This analysis will estimate the residual queues for each period and use them as the initial queues for the subsequent period for each lane group. This will allow for a more accurate computation of additional delays (d3) attributable to these queues for the overall analysis period. Another advantage to running a multiple-period analysis for any situation (including undersaturated conditions) is to overcome the dilemma in using the appropriate 15-minute period versus a peak-hour factor (PHF) that could vary among movements and periods.

What is the difference between demand used instead of volume in Signals?

Demand is the arrival rate and volume is usually taken to mean stop bar counts. Stop bar counts do not represent demand for congested conditions. In Signals, this plays a significant role in the determination of residual queues that are used to compute d3 delay. Counting the remaining queue at the end of each period is essential for determining total demand for every movement and period. For oversaturated situations, this can make a very significant difference in the overall delays and LOS.

What other requirements are there when collecting data for a Signals analysis?

There are several types of information required for a Signal analysis that can be obtained while performing turning movement counts: Residual queues (see above) for each period for all approaches; parking maneuvers per hour within 250 ft of the stop bar; buses stopping per hour within 250 ft (near side or far side); unequal lane distribution for a multiple lane movement; and right turns on red, pedestrians, and bicycles per hour on each approach.

What green times are required in Signals when analyzing actuated phasing?

The green times coded for actuated phases are the average durations for the period being analyzed. The minimum and maximum time settings usually shown on plan sheets can be used in the Actuated Estimation screen to generate the average phase times using HCM Chapter 16 Appendix B procedures.

How many generations should I run when Optimizing in Signals?

An increased number of generations allows for more optimization. Fewer generations will take less time, but may not produce the best results. Therefore, even though the default maximum number of generations is 20, this number must often be increased to 50 or higher in order to locate the optimum solution. Also, a narrow cycle length range will reduce the possibilities to be tested, and allow better results in a shorter time.

What is the I-Value in Signals and how is it computed?

The Upstream Filtering and Metering Adjustment Factor (I) accounts for the filtering effects of upstream signals within a mile of the analysis signal on each approach. It is based on the weighted average of the v/c ratios of the upstream contributing movements (automated in Signals) and can make a significant difference in the d2 delay, especially where the subject approach has v/c ratios approaching or exceeding 1.0.

How are Arrival Type values in Signals determined?

If the proportion of vehicle arriving on green is known, it is coded and the arrival type is computed for that lane group. If that proportion is not known, then the progression quality is used to subjectively determine arrival type. Arrival Type 3 should be assumed for all uncoordinated lane groups.

What is the Queue Storage Ratio in Signals and is it important?

The Queue Storage Ratio (QSR) is the Maximum Back of Queue (HCM Chapter 16 Appendix G) divided by the Available Queue Storage Length. If the QSR is equal to or greater than 1.0, blockage will occur. The HCM procedures do not account for this blockage in the computation of delay.

For protected-permitted phasing separated by an overlap phase, the lost time application may be incorrect in some cases. Please contact McTrans if you have this issue.

Displaying the Multiple-Period report while not in period one may modify the volumes temporarily. Closing the file without saving, then reopening the file restores the values, but saving the file at this point will save any incorrect volumes.

For data sets that include movements with 100% green time, there may be a divide by zero issue in the Supplemental Uniform Delay Worksheet. Please contact McTrans is you have this issue.

Unless you are using Windows Vista, uninstalling HCS+T7F will retain a few empty folders. An update to InstallShield corrected this for Vista, but other Windows users may still have these folders that can be safely deleted.

These issues are planned for correction in version 5.5, scheduled for release in the summer (after also implementing any approved changes by the TRB Highway Capacity and Quality of Service committee during the summer meeting).